Rotary offset sheet-printing press adapting it to perfect.



T. R. G. PARKER.

ROTARY OFFSET SHEET PRINTING PRESS ADAPTING IT TO PERFECT.

APPLICATION FILED NOV. 12, 1913.

1,131,950, Patented Mar. 16, 1915.

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THOMAS ROBERT GILLETT PARKER, 013 BR TYPE AND MACHINERY LIM ROTARY OFFSET SHEET-PRINTING PRESS ADAPTING IE' Application filed November 12, 1913.

To all whom it may concern:

Be it known that I, THoMAs ROBERT GIL- LETT PARKER, a subject of the King of the United Kingdom of Great Britain and he land, residing at Linotype and Machinery lVorks, Broadheath, in the county of Chester, England, have invented new and useful Improvements in Rotary Ofiset Sheet-Printing Presses Adapting Them to Perfect, of which the following is a specification.

The present invention is an improvement in or modification of the invention described and claimed in the specification of Letters Patent of the United States, No. 1,031,288, July 2nd, 1912, hereafter referred to as the original patent. In the latter, the form or plate cylinder has attached to it the usual aluminium or other lithographic plate which extends around practically one half of its circumference, and makes one complete revolution for each sheet printed, the cooperating offset and impression cylinders whose common diameter is only half that of the said form cylinder, making two revolutions each in the same time. Now, as only half the circumference of the form cylinder is a printing surface, it follows that the other half is vacant.

The object of the present invention is to make the press of the original patent, a perfecting one whenever it is desired so to do, and consists in a printing surface of any kind provided that it is a replica of the plate mentioned in the original patent, attached-- preferably detachably so-to the vacant half above mentioned. In addition to the attached plate being a replica, it must be attached in a position angularly opposite to that of the other plate in order that the impression made on the offset cylinder by the attached plate, may be exactly superposed upon that made by the said other plate.

A press according to the original patent adapted according to the present invention, to perfect, is capable of doing excellent work in printing transparencies.

Referring to the accompanying figure which is a diagrammatic side elevation, 1 is the form or plate cylinder; 2, part of the base and 3, part of a side frame of the press; 4, the ofiset cylinder; 5, the impression cylinder; 6, the damper; 7, the inker; 8, the feed board; and 9, a part of the delivery Specification of Letters Patent.

OADHEATH, ENGLAND, ASSIGNOR TO LING- ITED, OF LONDON, ENG-LAND.

TO PERFECT.

l atented ltltar. 16, 1:21.55. Serial No. 800,436.

'patent.

10 is the plate and 11, the sheet grippers which that patent called for.

12 is the replica of the plate 10, which the present invention calls for.-

Both 10 and 12 are shown as aluminium plates held to the respective halves of the circumference of the cylinder 1 by known means 18, but, as already pointed out, the replica 12 may be of any kind,-lithographic, typographic, planographic, or otherwise, subject to the stated proviso. Neither is there anything in the present invention to limit the printing surface 10 in respect of its kind.

The invention acts the first half revolution ter both plates 10 and 12 are ready for work, the plate 10 prints on and all the wax around the blanket on the cylinder 4: and the latter oifsets that impression on to the blanket on cylinder 5, the plates 10 and 12 having changed places and the cylinders 4 and 5 having assumed their original positions. During the second half revolution of the cylinder 1, a sheet is fed to the grippers 11 and is taken between the cylinders 4: and 5. The inner face of this sheet takes the impression then on the blanket on the cylinder 5 and the outer face of it takes the impression printed on the blanket on the cylinder 4 by the plate 12. The perfected sheet is then delivered. When either or both the printing surfaces 10, 12, are nonas follows: During of the cylinder 1 aflithographic, there are suitable means for-- putting the damper 6 out of action.

It may be that a press made according to the original patent will have automatic means for tripping the cylinder 1. If it has, these means must be altered so that they can be put out of action because the present invention requires that the three cylinders l, 4 and 5 which together constitute the perfecting combination, shall always be in printing relationship with each other. As both automatic means for tripping and means for putting them out of action are well known, and form no part of the present invention, and, besides, as any suitable kind can be used. it has not been thought necessary to illustrate one.

I claim In perfecting ofiset sheet presses, a perfecting mechanism consisting of a plate or form cylinder having two printing surfaces each a replica of the other and both angularly opposite to each other; an offset cylinder of half the diameter of the former and having its entire periphery cooperating with each printing surface in turn and each succeeding impression superposed exactly upon the preceding one and an impression cylinder of the same diameter as the offset cylinder and cooperating therewith; the arrangement being such that during each revolution of the plate cylinder, a sheet is printed on one side by the impression cylinder with the impression ofiset on to the offset 15 cylinder by one of the printing surfaces and perfected by the ofiset cylinder with the inipression superposed by the other of the said surfaces. on the immediately preceding one.

In witness whereof I have hereunto set 20 my hand in the presence of two Witnesses.

THOMAS ROBERT GILLETT PARKER.

Witnesses:

EWALD SIMPSON MosELEY, MALCOLM SMnTHURs'r.

Copies of this patent may be obtained for five cents each, by addressing the Gommissioner of Patents. Washington, D. G. 

